/**
 * 
 * APDPlat - Application Product Development Platform
 * Copyright (c) 2013, 杨尚川, yang-shangchuan@qq.com
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 * 
 */

/*
 * Map对象，实现Map功能
 *
 *
 * size() 获取Map元素个数
 * isEmpty() 判断Map是否为空
 * clear() 删除Map所有元素
 * put(key, value) 向Map中增加元素（key, value) 
 * remove(key) 删除指定key的元素，成功返回true，失败返回false
 * get(key) 获取指定key的元素值value，失败返回null
 * element(index) 获取指定索引的元素（使用element.key，element.value获取key和value），失败返回null
 * containsKey(key) 判断Map中是否含有指定key的元素
 * containsValue(value) 判断Map中是否含有指定value的元素
 * keys() 获取Map中所有key的数组（array）
 * values() 获取Map中所有value的数组（array）
 *
 */
function Map(){
    this.elements = new Array();
 
    //获取Map元素个数
    this.size = function() {
        return this.elements.length;
    },
 
    //判断Map是否为空
    this.isEmpty = function() {
        return (this.elements.length < 1);
    },
 
    //删除Map所有元素
    this.clear = function() {
        this.elements = new Array();
    },
 
    //向Map中增加元素（key, value) 
    this.put = function(_key, _value) {
        if (this.containsKey(_key) == true) {
            if(this.containsValue(_value)){
                if(this.remove(_key) == true){
                    this.elements.push( {
                        key : _key,
                        value : _value
                    });
                }
            }else{
                this.elements.push( {
                    key : _key,
                    value : _value
                });
            }
        } else {
            this.elements.push( {
                key : _key,
                value : _value
            });
        }
    },
 
    //删除指定key的元素，成功返回true，失败返回false
    this.remove = function(_key) {
        var bln = false;
        try {  
            for (i = 0; i < this.elements.length; i++) {  
                if (this.elements[i].key == _key){
                    this.elements.splice(i, 1);
                    return true;
                }
            }
        }catch(e){
            bln = false;  
        }
        return bln;
    },
 
    //获取指定key的元素值value，失败返回null
    this.get = function(_key) {
        try{  
            for (i = 0; i < this.elements.length; i++) {
                if (this.elements[i].key == _key) {
                    return this.elements[i].value;
                }
            }
        }catch(e) {
            return null;  
        }
    },
 
    //获取指定索引的元素（使用element.key，element.value获取key和value），失败返回null
    this.element = function(_index) {
        if (_index < 0 || _index >= this.elements.length){
            return null;
        }
        return this.elements[_index];
    },
 
    //判断Map中是否含有指定key的元素
    this.containsKey = function(_key) {
        var bln = false;
        try {
            for (i = 0; i < this.elements.length; i++) {  
                if (this.elements[i].key == _key){
                    bln = true;
                }
            }
        }catch(e) {
            bln = false;  
        }
        return bln;
    },
   
    //判断Map中是否含有指定value的元素
    this.containsValue = function(_value) {
        var bln = false;
        try {
            for (i = 0; i < this.elements.length; i++) {  
                if (this.elements[i].value == _value){
                    bln = true;
                }
            }
        }catch(e) {
            bln = false;  
        }
        return bln;
    },
 
    //获取Map中所有key的数组（array）
    this.keys = function() {
        var arr = new Array();
        for (i = 0; i < this.elements.length; i++) {  
            arr.push(this.elements[i].key);
        }
        return arr;
    },

    //获取Map中所有value的数组（array）
    this.values = function() {
        var arr = new Array();
        for (i = 0; i < this.elements.length; i++) {  
            arr.push(this.elements[i].value);
        }
        return arr;
    };
}